I am trying to write a controller that will calculate the driving distance between the account and a lookup field on the account, called Facility__c.  Facility__c is attached to the Object Facility__c that needs to be referenced.  How do I fix my code?
 

public with sharing class CalculateDistanceMatrixGoogleMapsCtrl {
    public String accountId				{get;set;}
    public Account account1				{get;set;}
    public String account1Address		{get;set;}
    public String FacilityId			{get;set;}
    public String facility2				{get;set;}
    public String facility2Address		{get;set;}
    public CalculateDistanceMatrixGoogleMapsCtrl() {
        updateAccounts();
    }
    
    public List<Account> getAccounts() {
        return accounts;
    }
    
    public List<Facility__c> getFacilities() {
        return facilities;
    }
    
    public void updateAccounts() {
        
        if (!accounts.isEmpty()) {
            accounts.clear();
        }
        
        this.accounts = [SELECT ID, Name, ShippingStreet, ShippingCity, ShippingState, ShippingPostalCode, ShippingCountry FROM Account WHERE ShippingStreet <> '' LIMIT 1];
        
    }
    
    public void updateFacilities() {
        
        if (!facilities.isEmpty()) {
            facilities.clear();
        }
        
        this.facilities = [SELECT ID, Name, Street_Address__c FROM Facility__c WHERE Street_Address__c <> '' LIMIT 1];
        
    }
    
    public void updateAccountVariables() {
        
        for (Account a : accounts) {
            if (a.ID == accountId) {
                account1 = a;
            }
        }
        for (Facility__c f : facilities) {
            if (f.ID == facilityId) {
                facility2 = f;
            }
        }
    }
    
    public Boolean updateAccountAddresses() {
        
        if((
        		String.isBlank(account1.ShippingStreet)
        		&& String.isBlank(account1.ShippingCity)
        		&& String.isBlank(account1.ShippingState)
        		&& String.isBlank(account1.ShippingPostalCode)
        		&& String.isBlank(account1.ShippingCountry)
        ) && (
            String.isBlank(facility2.Street_Address__c))) {
                
                ApexPages.addMessage(new ApexPages.Message(ApexPages.Severity.FATAL, 'Impossible build addresses for API call. Some fields are missing'));
                return false;
                
            }
        
        account1Address = EncodingUtil.urlEncode((
        	account1.ShippingStreet + ' ' +
        	account1.ShippingCity + ' ' +
        	account1.ShippingState + ' ' +
            account1.ShippingPostalCode + ' ' +
            account1.ShippingCountry).trim(),
            'UTF-8');
        
        facility2Address = EncodingUtil.urlEncode((
        	facility2.Street_Address__c).trim(),
            'UTF-8');
        
        System.debug('*** account1Address: ' + account1Address + ' , facility2Address: ' + facility2Address);
        return true;
    }
    
    public List<SelectOption> getAccountOptions() {
        
        List <SelectOption> options = new List <SelectOption>();
        options.add(new SelectOption('', '--None--'));
        for (Account a : accounts) {
            options.add(new SelectOption(a.Id, a.Name));
        }
        return options;
    }
    
    public void btnCalculateDistance() {
        
        if ((account1Id == null || account1Id =='') || (facility2Id == null || facility2ID =='')) {
            ApexPages.addMessage(new ApexPages.Message(ApexPages.Severity.INFO, 'Select two Accounts then resubmit'));
            return;
            
        }
        
        updateAccountVariables();
        boolean response = updateAccountAddresses();
        if (response) {
            CalculateDistanceMatrixGoogleMaps gm = new CalculateDistanceMatrixGoogleMaps(account1Address, facility2Address);
            this.distance = isNull(gm.distance) ? 0.0 : gm.distance;
            this.duration = isNull(gm.duration) ? 'empty' : gm.duration;
            this.travelTime = isNull(gm.travelTime) ? 0 : gm.travelTime;
        } else {
            this.distance	=0.0;
            this.duration	='empty';
            this.travelTime	=0;
            
        }
    }
    
    public List <Account> accounts =new List <Accounts>();
    
    public Decimal distance		{get; set;}
    public String duration		{get; set;}
    public Integer travelTime	{get; set;}
    
    public Boolean isNull(Object obj) {
        if (obj == null) {
            return true;
        }
        if (obj instanceof String) {
            if ((String)obj == '') {
                return true;
            }
        }
        if (obj instanceof Decimal) {
            if ((Decimal) obj == 0.0) {
                return true;
            }
        }
        if (obj instanceof Integer) {
            if ((Integer) obj == 0) {
                return true;
            }
        }
        return false;
    }
    
    public Boolean isDigit(Object obj) {
        Pattern p = Pattern.compile('^\\d+$');
        Matcher m = p.matcher((String)obj);
        if (m.find()) {
            return true;
        }
        return false;
    }
    
    public Boolean isText(Object obj) {
        Pattern p = Pattern.compile('^[a-zA-Z ]*$');
        Matcher m = p.matcher((String)obj);
        if(m.find()){
            return true;
        }
        return false;
    }
}